Problem: Simplify the following expression: $r = \dfrac{-8t}{2} - \dfrac{-2t}{2}$
Answer: Since the expressions have the same denominator we simply combine the numerators: $r = \dfrac{-8t - (-2t)}{2}$ Combine like terms: $r = \dfrac{-6t}{2}$ Simplify by dividing numerator and denominator by 2: $r = \dfrac{-3t}{1}$ $r = -3t$